The Joint Tactical Radio System was an amazing concept put forward by the US military. It was designed to future-proof the entire communications system used by all US defense organizations, which is why it required 15 years of work and the investment of $6 billion dollars. Sadly, things didn't go to plan.

Ars Technica has a wonderful feature about how the US military came to blow such a huge stack of cash on the project. It sought to create a universal "operating system" for military radios, one that would simplify the use of radio in the field, and make systems cheaper and easier to upgrade. Sadly, it reached a little further than it was able to manage. From the article:

"Military technology often pushes at the edge of the doable-that's why agencies like DARPA exist. But when JTRS was originally conceived in 1997, the Army's most significant previous work on software-defined radio was an Army project called SpeakEasy-the first version of which took up the entire back of a military truck. Clearly, an ambitious project like JTRS had plenty of basic research to chew through before it could produce anything useful. In hindsight, the military badly underestimated the challenges before it."

A lack of experience and, not least, understanding meant the project was doomed from the get-go. The only output from the project was a radio device which weighed in at a staggering 207 pounds, which wasn't so practical out in the field. For a further look into the project, the Ars Technica feature makes a really entertaining read. [Ars Technica]